In an MCU (Micro Controller Unit) for a power conversion application in which real-time properties such as full digital power-supply control and motor control are regarded as important, for example, a conversion end event from an A/D converter, an inversion detection event a comparator, and a timing event from a PWM (pulse width modulation) timer are output respectively and there is a necessary that process which should be performed in response to each event is performed without a delay time.
Hereinafter, although this technology will be disclosed especially in association with digital power-supply control, since the essence of feedback control does not change, the contents of this disclosure are applied exactly in the same way in a case where this is any other power controls including motor control.
In Japanese Patent Application Laid-Open No. 2013-25590, there has been disclosed an MCU which independently operates a DMAC (Direct Memory Access Controller) and a CPU (Central Processing Unit).
In this MCU, if an A/D converter ends conversion, the DMAC transmits data from a conversion result register of the A/D converter to a data register of a DSP (Digital Signal Processor), and starts up an arithmetic processing sequence of the DSP. If the arithmetic processing sequence of the DSP ends, the DMAC transmits the result data of the arithmetic processing sequence to a duty setting register of a PWM timer. If this series of processing is applied, for example, linear control (phase compensation using a digital filter) in a digital power supply is able to be performed without intervention of the CPU.